Today's best sandwiches upend old notions about what belongs between two slices of bread. Although lettuce and mayo haven't gotten the boot, America's most notable sandwich artisans no longer feel obliged to include them. "We look at the sandwich with a more open mind," says Sisha Ortuzar, a partner in New York City–based 'Wichcraft, the sandwich emporium whose principals include celebrity chef Tom Colicchio. "You can make anything into a sandwich. It just happens to be in portable form."

Chefs like Donald Link at New Orleans's recently opened Cochon Butcher Shop apply the same finicky standards to sandwiches that they do to the rest of the menu. Cochon's muffuletta admits only house-cured meats, from mortadella to Genoa salami to supple sliced ham. The chef also prepares his own giardiniera, the signature olive relish that marks a muffuletta.

Handmade elements also elevate the Tunisian spicy tuna sandwich at Alon's, an Atlanta bakery/market operated by chef Alon Balshan. Raised in melting-pot Israel, Balshan plumbed childhood memories for this spicy Tunisian version of the Provençal pan bagnat. He makes the harissa (North African red-pepper paste), the preserved lemons and even the crusty baguettes for his sandwich, a nosh likely to make tasty memories for Atlantans, too.

The inspiration for Brasil's chicken-salad sandwich "came from knowing what appeals to us Texans," says Magda Sayeg, one of the co-proprietors of the 15-year-old Houston café. "We like our spice." Laced with poblano chilies, black beans, jicama and lime, the sandwich has a fixed spot on a menu that has steadily evolved since Brasil's early days as a coffeehouse/art gallery.

Even America's beloved BLT gets a new look in the kitchen of a Chicago chef steeped in deconstruction. "We're the type of restaurant that would lead you to think that if you order a BLT, you're not going to get a bacon, lettuce and tomato sandwich," admits Daryl Nash, the chef at Otom, whose sister restaurant is the cuttingedge Moto. Caramel-braised pork belly, lettuce purée and tomato jam figure in Nash's playful remake, a layered concept that pits crisp against creamy.

'Wichcraft's grilled panino with Gruyère and green-olive tapenade hasn't landed a spot on the menu, but it's a behind-the-scenes hit with employees. "We also make it for customers who want something a little different," says Ortuzar, himself a fan of this Mediterranean-inflected grilled cheese.

There are those who think bread and chocolate is the gods' own breakfast, but Hi-Rise Bread Company's Sin Sandwich brings the duo to mortals. Only an accomplished baker can produce a flaky pain au chocolat, but anyone can grill a sandwich of Nutella and dark chocolate on store-bought brioche—and everyone probably should at least once. At the Cambridge, Massachusetts, bakery, customers tend to share the oozy, sugar-dusted sandwich—but given the name, it shouldn't be split too many ways.